For Sarah Thomson, crossing over to George Smitherman was like a journey of a thousand miles that ended, literally, with a few steps.

The office where the political neophyte toiled around the clock for nine months is less than a block from Smitherman headquarters on The Esplanade.

So Ms. Thomson didn't have far to march to officially endorse the former deputy premier and possibly change the course of the mayoral race.

It's too early to say whether the Women's Post publisher will be able to deliver votes for Mr. Smitherman on Oct. 25, but her support provides him a significant psychological boost just one day after a new poll found the gulf between Mr. Smitherman and front-runner Rob Ford has shrunk to five percentage points.

"I think all of this tells us the sands are shifting," said Myer Siemiatycki, a municipal politics expert at Ryerson University. "It is becoming a considerably closer race and there is a lot of momentum behind Mr. Smitherman."

That fresh momentum may have less to do with Mr. Smitherman's lacklustre campaign than the prospect of Mr. Ford becoming mayor.

It was the strong possibility of the latter, after all, that helped persuade Ms. Thomson to end her improbable run.

"To see Rob Ford polling up when we all knew it was over anger …` it was a sad situation," she told The Globe and Mail in an interview Tuesday. "That's the moment when I realized, look, I've got to show Toronto what Rob Ford is like."

She opted to back Mr. Smitherman in part because polls indicate he has the best shot at beating Mr. Ford, but also because his platform most closely resembles her own. His financial plan, released Monday, also impressed her.

"He's got the brains to really move the city forward," she said.

Ms. Thomson transitioned swiftly into her new role as Smitherman champion, joining him for a ribbon-cutting at the new Women's College Hospital while her campaign staff discussed integrating with their old rivals, according to campaign manager George Tory.

"But no firm commitments have been made," he cautioned.

Although she had been speaking to the other camps for a few weeks, Ms. Thomson made her final decision Monday night after an Ipsos-Reid poll of 400 Torontonians showed Mr. Smitherman, at 23 per cent, within striking distance of Mr. Ford, who sits at 28-per-cent support.

Conducted Sept. 24-26, the poll is accurate within 4.9 percentage points, 19 times out of 20.

She lagged behind at 7-per-cent support, tied with Rocco Rossi and three points behind Joe Pantalone.

Both insist they won't follow Ms. Thomson's lead.

"My future is clear: Eight years from now, after I serve my second term as mayor, I'll retire," Mr. Pantalone said.

Mr. Rossi is equally committed. "My internal polling suggests very strongly the bulk of her support will come to me," he said, emphasizing that he and Ms. Thomson are both business types who've never held elected office.

Indeed, a small slice of a Nanos Research telephone poll conducted Sept. 14-16 suggests scant Thomson support would migrate to Mr. Smitherman.

Of 49 people who identified themselves as Thomson voters, only one identified Mr. Smitherman as a second choice. Eleven picked Mr. Rossi, 10 picked Mr. Pantalone, 10 picked Mr. Ford and 17 had no second choice.

A spirited competitor and the only serious female candidate in the race, Ms. Thomson became a legitimate contender with a bold proposal to install road tolls to pay for an expanded subway system.

Along the way, she picked up some high-profile supporters, including two of John Tory's sons and former media baron Conrad Black.

But she didn't pick up much cash. She only raised about $75,000 over the course of the campaign and spent approximately $150,000, meaning she's saddled with a large campaign debt.

But all that hasn't turned the married mother of two off elected life. She's itching for a future in politics, though she's not sure when, or for which party, she'll run next. "I've got the bug," she said.

In the meantime, she'll devote the next four weeks to helping Mr. Smitherman win the mayor's chain. Asked how she plans to aid his campaign, she proved her sense of humour has survived the gruelling race.

"Well, I'm not going to strip for him," she said, laughing.

With a report from Anna Mehler Paperny